Performance Of Reactor System Research Articles

Oligomerization of Fischer–Tropsch Tail Gas over H-ZSM-5

Fischer–Tropsch synthesis produces a product that invariably contains C4 and lighter material. The C2–C4 fraction has a high olefin content. The light hydrocarbons in the Fischer–Tropsch tail gas can be separated from the unconverted synthesis gas, but the added cost and complexity of doing so by pressure distillation is often considered unjustified. In this study the possibility of reactive recovery of the C2–C4 olefins from the Fischer–Tropsch tail gas by oligomerization over H-ZSM-5 was investigated. Two specific issues were investigated for this unconventional application of this industrially practiced technology, namely, to determine the impact of low olefin partial pressure on productivity and to determine whether acid catalyzed CO reactions, such as the Koch reaction, were taking place. Catalyst and reactor system performance was evaluated using model propylene oligomerization. A catalyst productivity of 0.42 g·(gcat)−1·h–1 was achieved with a 39% C3H6 feed at 190 °C, 3 MPa, and weight hourly space...

Performance of a hybrid anaerobic-contact oxidation biofilm baffled reactor for the treatment of decentralized molasses wastewater

A novel hybrid anaerobic-contact oxidation biofilm baffled reactor (HAOBR) was developed to simultaneously remove nitrogenous and carbonaceous organic pollutants from decentralized molasses wastewater in the study. The study was based on the inoculation of anaerobic granule sludge in anaerobic compartments and the installation of combination filler in aerobic compartments. The performance of reactor system was studied regarding the hydraulic retention time (HRT), microbial characteristics and the gas water ratio (GWR). When the HRT was 24h and the GWR was 20:1, total ammonia and chemical oxygen demand (COD) of the effluent were reduced by 99% and 91.8%, respectively. The reactor performed stably for treating decentralized molasses wastewater. The good performance of the reactor can be attributed to the high resistance of COD and hydraulic shock loads. In addition, the high solid retention time of contact oxidation biofilm contributed to stable performance of the reactor.

Continuous phenol hydroxylation over ultrafine TS-1 in a side-stream ceramic membrane reactor

A side-stream ceramic membrane reactor system was developed that can facilitate the in situ separation of ultrafine catalysts from the reaction mixture and make the production process continuous. Continuous hydroxylation of phenol to dihydroxybenzene over ultrafine titanium silicalites-1 (TS-1) was taken as a model reaction to evaluate the feasibility and performance of the membrane reactor system. The effects of membrane pore size and operation conditions (residence time, temperature, catalyst concentration, phenol/H2O2 molar ratio) on the performance of the reactor system were examined via single factor experiments. We demonstrated that the membrane pore size and operation conditions greatly affect the conversion, selectivity and filtration resistance. The phenol conversion and dihydroxybenzene selectivity remain stable at about 11% and 95% in a 20-h continuous run, respectively.

The Attainable Region for Segregated, Maximum Mixed, and Other Reactor Models

It is common practice in process synthesis to choose a reactor structure and use the free parameters associated with it to optimize the system. It is of some importance to assess how effective such an approach is. A geometric (attainable region) approach is used to find the bounds on the performance of reactor systems, and these are compared with the complete attainable region. It is shown for instance that the conversions obtained in segregated and maximimum mixed reactors are not general bounds on conversion. Even two or more environment reactor models need not be sufficiently general to provide bounds on conversion. Given a proposed reactor system, it is thus possible to compare the achievable conversions with those of the complete attainable region. This provides a useful test to determine whether significant improvements in reactor performance can be obtained by using alternative reactor structures